The US Air Force (USAF) is seeking an interim 500 lb-class weapon with a moving target capability for the Lockheed Martin F-35 Lightning II Joint Strike Fighter (JSF).

A `sources sought' notice posted on the Federal Business Opportunities website on 10 February calls for information from the US industry only on a non-developmental precision-guided munition (PGM) capable of being integrated onto the F-35A, ahead of an expected request for proposals (RFP).

As noted by the Air Combat Command's request for information (RFI), an initial 400 weapons are being sought of a total inventory of 1,200. The first contract is expected to be awarded in the third quarter of fiscal year 2017, with deliveries of the initial order to begin no later than six months after the contract date.

"In response to an Air Combat Command (ACC) Quick Reaction Capability (QRC) requirement, the USAF is seeking a time sensitive, interim solution to add a 500 lb-class Precision Guided Munition (PGM) with moving and manoeuvring target capability that is mechanically, electrically, and logically compatible with F-35 Block 3F aircraft Operational Flight Program (OFP) {in other words no software changes}. This munition must consistently impact moving targets traveling along a constant heading with a uniform velocity up to 70 mph and manoeuvring targets performing ±0.2 g manoeuvres with velocities up to 40 mph. The capability cannot impact the current fielding schedule for F-35 Block 3F, namely 15 May 2018," the RFI states.

Responses are due no later than 15:00 Central Daylight Time (CDT) 12 March.

The F-35A is already earmarked to carry the Raytheon GBU-12 500 lb PGM and the GBU-38 500 lb Joint Direct Attack Munition (JDAM), but these weapons do not currently have the required moving target capability.

Possible contenders for the requirement include the Boeing GBU-54/B Laser JDAM based on the MK 82 or BLU-111 500 lb bombs; as well as the Lockheed Martin Dual Mode Plus LGB kit fitted to the MK 82 or BLU-111.(343 of 516 words)

Doesn't moving target capability imply some sort of autonomous seeker head -- either IIR or millimeter wave radar? If Wikipedia is correct, Paveway IV only has laser and GPS/INS guidance, so that would not seem to fit the bill. If the laser does fit the bill, why wouldn't any Paveway laser-guided bomb then fit the requirement too?

Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.

Moving target means moving target, has nothing to do with seeker head design. It does not preclude laser terminal illumination.

GBU-12 can hit moving targets, but requires a considerable amount of user intervention to do so effectively.

AFAIK, dual mode Paveway/P2E are comparable to PIV, where the weapon itself removes much of the user intervention required with vanilla P2. I think this is a case of "not made here", when it comes to the PIV. To be fair, however, with 2 domestic sources for 3 models of valid weapons, there's a good argument for doing a little bit of extra work to tap into that existing domestic inventory/production capacity.

Why is there a need for a 500lb bomb capable of hitting targets moving up to 70mph? Doesn't SDB I & II have that ability along with the forthcoming SPEAR? What moves at 70mph that would not survive SDB or SPEAR? Or is this a timing issue -- needing something in the inventory ASAP (i.e. yesterday) until SDB / SPEAR are available?

Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.

bojack_horseman wrote:Also, what moving object requires such a large bomb to destroy?

That's what I'm saying!

However, if we re-phrase the question as: "What is the smallest Block 3F weapon that can engage a moving target?" then the question makes more sense and the answer would appear to be a laser guided 500lb Mk82 derivative.

Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.

That's exactly what they are looking for. The weapon has to talk to the F-35 using the same modes & codes as the existing Paveway or JDAM so that they do not need to change any F-35 Codes. They are basically looking for updates to current Block3F 500lb weapons that do not require new F-35 software and that also meets the new target speed requirements.

I wonder if Boeing's SDB1 with a laser seeker would fit the bill. Not sure if it can engage a 70mph target but I doubt that it can use laser designation with the same Blcok3F SDB interface.

500lb worth of killing power gives you extra margin against tanks and armored VBIED.

There is a 250lb class warhead (the Alternative Warhead that replaced DPICMs) developed that should do the job as well, if one integrated that into the SDB I, but then it's not technically an OTS solution.

Not sure if LSDB can be 4 packed as per normal SDB, they seem a bit long for that. Still, a 2 pack of SDB gives you more option than a single 500lb.

Keep in mind the overall limit (for this solicitation) to introducing any new functionality is that it has to conform to the weapon software in Block3F. Once Block 4.x & UAI comes along, the floodgates of available weapons will be opened. This solicitation is more about an interim weapon till 4.x comes out.

If I'm not mistaken, Paveway IV is only bought by the RAF so the US has no or very limited stock. If a laser fits the bill, it sounds like the GBU-54 LJDAM as the article suggests. I don't remember seeing any orders for DMLGBs in the budget docs so if they want something in service that's about all they got...

LJDAM is not a valid choice because it is not included in Block3F software. The weapon that is chosen has to be software compatible with a Block3F F-35. This is why they are looking at accuracy updates for existing Block3F weapons.

LJDAM is built off of JDAM, so the baseline software for aircraft-weapon communication is there. GBU-12 does not involve that kind of software, so P2E and DMLGB would have to rely on any available software commonality with the JDAM.

In the second production lot, the existing GPS guidance unit was improved. In order for the Paveway IV to better attack moving targets, up to 70mph, a number of software improvements have been progressively implemented with trials completed in 2014. Enhanced anti-GPS jamming capability has also been developed.

Not only does it add GPS to the LGB, but it also provides for a programmable fuse (air-burst, point detonate, delayed detonate).